This study investigates how generative artificial intelligence can be transformed from a text-producing tool into a cognitive scaffold in academic writing instruction. A quasi-experimental study was conducted with 64 first-year university students (aged 17–19) enrolled in an English-medium program in Uzbekistan. Participants were divided into the AI- Assisted Writing Group using conventional AI-assisted writing and the Socratic-AI Guided Writing Group applying a structured Socratic-AI scaffolding model. Over eight weeks, students completed argumentative writing tasks. Results show that the experimental group demonstrated greater improvement in argument structure, logical coherence, and metacognitive awareness. The findings suggest that structured Socratic prompting can reposition AI from a passive writing assistant to an active cognitive mediator in academic writing development.